Right side universal electrocardiogram sensor positioning mask and method

ABSTRACT

A universal and reversible disposable ECG sensor positioning mask and method for use with electrocardiogram diagnostic equipment for left and right chest ECGs in which the mask has at least nine sensors, six of which can be used at any one time to provide up to four different sizes to accommodate varying sized human torsos.

RELATED APPLICATIONS

This is a continuation-in-part of U.S. patent application Ser. No.10/021,937, filed on Dec. 13, 2001, now U.S. Pat. No. 6,553,246, issuedApr. 22, 2003, for a Universal Electrocardiogram Sensor PositioningDevice and Method which is a continuation-in-part of U.S. patentapplication Ser. No. 09/461,701, filed on Dec. 14, 1999, now U.S. Pat.No. 6,400,977 BI, issued Jun. 4, 2002, for A Universal ElectrocardiogramSensor Positioning Device and Method, which is a continuation of U.S.patent application Ser. No. 09/022,730, filed on Feb. 12, 1998, now U.S.Pat. No. 6,006,125, issued Dec. 21, 1999.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a disposable dermal chest mask forassistance in establishing electrical communication between sensors on ahuman chest and electrocardiograph machines. More particularly, itrelates to a universal electrocardiogram sensor positioning mask andmethod for the right side of human chests for all adult sizes includingsize extra large.

2. Description of the Prior Art

Diagnostic medical equipment increasingly relies upon electrical contactwith specific areas of the human body for evaluating the health statusof patients. One of the most utilized and relied upon diagnostic toolsis the electrocardiogram, sometimes referred to as an ECG. Leads orsignal wires from the analytical apparatus are attached to a metallic orotherwise conductive body sensor electrode which is attached to thepatient's skin at the desired points of contact. Electrical currentgenerated by the heart in a person's chest flows to the surface and atthe skin produces differences in electrical voltage which can bemeasured between pairs of electrodes placed at two points on the skin. Atwelve-lead electrocardiograph is the most utilized for recognizingischemic electrocardiographic changes.

To administer a resting twelve-lead ECG, it is necessary to apply tenelectrodes to various points on the torso and limbs of a patient tomeasure and analyze cardiac data. Twelve recordings for the ECG are madefrom nine active lead positions with the tenth being used as a ground.An electrode portion of a lead may in fact consist of an alternativeform of sensor, and the terms “electrode” or “sensor” for purposes ofthis disclosure are interchangeable. A lead wire connecting a sensor tothe diagnostic equipment could possibly in fact consist of a radio or anoptical signal. Six of the ten electrodes are applied to the patient'schest over prescribed anatomical landmarks. The remaining fourelectrodes are applied to each of the patient's limbs. The chestelectrodes are known as the precordial leads and the limb electrodes arecalled limb leads. The precordial leads are designated V₁, V₂, V₃, V₄,V₅, and V₆. The limb leads are designated LA, RA, LL, and RL (ground).

It is generally acknowledged that it is critically important to placethe precordial leads with precision in order to obtain accurate andrepeatable recordings. However, accurate placement and attachment of alarge number of leads can be difficult and time consuming and requiresknowledge, skill, and diligence on the part of the person attaching theelectrodes or sensors. Mechanical problems in attaching multiple leadsto a patient range from tangling of lead wires, and excessive timeconsumed in pairing lead wires with the appropriate electrodes, todifficulty in locating anatomical landmarks on a patient with precision.

Problems occur if the leads are not properly placed and are locatedhigher or lower than optimal. The position of the precordial leads isdetermined by the anatomical features of the patient's chest and not bythe position of the heart itself. Research reported in theelectrocardiography literature indicates that precordial leads placedone inch or more from their true anatomical landmarks can result inmisinterpretation of the patient's ECG. This may result in or contributeto diagnosis errors, false hospital admissions, sending sick peoplehome, or have other negative impacts on diagnosis or treatment. Theplacement problem is compounded when serial comparisons are made betweentwo or more ECGs taken over time. For example, if V₄ was placed one inchtoo high for one test and one inch too low for another, the differenceof two inches may produce what appears to be a significant differencebetween the two ECGs when in fact there was no physiological change inthe patient's heart condition.

To place the precordial leads accurately requires training in using bothvisual and palpatory cues to find the anatomical landmarks on eachpatient. Placement accuracy is also affected by the time and diligencededicated to placing the precordial electrodes. An experienced andconscientious electrocardiologist may require and devote ten minutes topalpation and ascertaining the exact precordial landmarks. However, inbusy clinical environments or emergency situations, medical personnelare often so rushed they may not even palpate the patient. Under thoseconditions, precordial leads are commonly placed with inadequatepalpation and with little attention to a patient's particular anatomy.As a consequence, individual leads are often misplaced by two and asmuch as three inches from their true anatomical landmarks. In addition,training and maintaining the necessary skill for proper placement ofindividual leads is time and resource consuming and often not adequate.With six precordial leads, there are six chances to misplace electrodes.Research shows that V₁ and V₂ electrodes are typically placed high andwide of their targets—the fourth intercostal space on each side of thesternum. Likewise, precordial electrodes V₄, V₅, and V₆ are most oftenmisplaced low and wide. Electrode V₃ is most often misplaced too low.The most obvious conclusion to be drawn is that lead placement is oftennot accurate.

After the individual electrodes are positioned on a patient, it isnecessary to attach the ten lead wires. Each lead wire is labeled tocorrespond to one of the anatomical landmarks, i.e., V₁, V₂ . . . V₆ . .. RL. Should lead wires be crossed, interpretative ECG monitors candetect and alert the operator of a possible crossed lead wire situation,but that requires additional time to check connections and to takecorrective action. This is a time consuming operation which increasesthe risk in an emergency situation. Crossed lead wires are a moresignificant problem when the ECG monitor does not provide interpretationof the recordings and cannot alert the operator of this possibility. Insuch a case, the ECG signals for each of the twelve leads are recordedon hard copy to be read at a later time. The physician or technicianreading the ECG recordings may recognize the error but by that time thepatient has usually been disconnected from the monitor. The presentinvention reduces or eliminates the chances of either of thesesituations from occurring.

Periodic electrocardiograms are important for providing a cardiographicprofile of a patient for early detection and diagnosis of cardiovasculardiseases. In order to provide an accurate profile, it is important notonly that the electrocardiogram be taken with sensors affixedaccurately, but that the sensors be placed at the same location on thepatient in the subsequent exam as for the previous examination. Theefficacy and the repeatability of the tests is critical so that a seriesof ECG results can be compared to provide a continuing profile of apatient's medical history for diagnosis and treatment of heart disease.

In urgent situations, including those electrocardiograms taken with thecurrent standard electrode lead wire system, during an acute symptomaticepisode there may only be time to attach two to four individualelectrodes to the patient. Therefore, it is desirable to have a maskwhich enables more electrodes or sensors to be quickly and accuratelysecured during such an acute symptomatic episode. Alternatively, it maybe necessary to quickly remove some or all of the chest leads when apatient is experiencing a heart attack or in other emergencies in orderto administer CPR, to massage the heart, administer drugs, to applyelectrical defibrillation paddles, or for other purposes. Accordingly,critical time can be lost both in the removal of the chest leads of theECG test equipment in order to administer aid to a patient and in theirsubsequent replacement after aid has been administered.

Because of the inadequacies of prior art devices to solve theseproblems, there has been a need for a system which: prevents or curtailsthe possibility of ECG electrode leads or wires from being entangled orcrossed; provides quick removal of some of the sensors when it isnecessary to administer aid to a patient having a heart attack; providesaccurate and appropriate repeatable placement of electrodes atsubstantially the same location on the patient; accurately andrepeatedly obtains signals from electrodes by efficient and effectiveelectrical transmission; and may be attached by persons with varyinglevels of experience including those with little training.

The inventions disclosed in the five related patents to Kelly—U.S. Pat.No. 5,865,740, No. 5,865,741, No. 5,916,159, No. 6,066,093, and No.6,157,851—involve various alternatives for the purpose of trying toeffect those goals. The common invention in those patents is adisposable electrode positioning mask that utilizes a non-conductingflexible sheet in the form of a mask having a predetermined dimensionalsensor array. The flexible sheet serves as a template for aligningconnectors or sensors, either of the electrode or electrodeless type, onthe chest of a patient for transmitting electrical impulses.

An important aspect of the Kelly inventions is that the flexiblenon-conductive sheet is provided in a plurality of sizes, with each sizehaving arrays V₁, V₂, V₃ and V₄, at substantially the same locations andhaving arrays V₅ and V₆ at different locations depending on size. Inthis regard, the locations of V₅, and V₆ are based on a measureddistance between the left midclavicular line and the left midaxillaryline on the chest of a patient.

An alternative of the related inventions is that the dimensional arrayon the flexible non-conductive sheet is provided with cutouts to form atemplate or mask which is placed on the patient's chest and thenconventional electrodes can be positioned in the cutouts. Still anotheraspect of the related inventions is that the template can be providedwith a plurality of conventional tab, snap, or other electrodes affixedon their top sides to the flexible sheet to be placed against thepatient's chest. The electrodes are positioned in accordance with thepredetermined dimensional array. Small cutouts, or openings, in thetemplate expose the electrode tabs for attaching lead wire clips. Snapelectrodes protrude through the template to permit the attachment oflead wire snap connectors.

In a further aspect of the related inventions, the top sides ofindividual electrodes can be lightly affixed to the flexible sheet ofmaterial at the predetermined dimensional array locations. The sheet canbe placed on the patient's chest and then peeled away leaving theelectrodes properly located on the chest. Each of these concepts can beemployed in the concept of the basic embodiment of the present inventionas disclosed in the related patent application and U.S. Pat. Nos.6,006,125 and 6,400,977 BI, designated earlier.

Yet another aspect of the Kelly inventions is a method of sizing apatient for fitting a sensor positioning mask having a flexible sheetwith a fixed dimensional V₁-V₆ array positioned in a specific sizeconfiguration appropriate for standard electrocardiographic recording.The distance between V₁ and V₂ is a predetermined distance plus or minusa small amount, and the distance between V₂ and V₄ is a predetermineddistance plus or minus a small amount, with V₃ located substantiallymidway between V₂ and V₄, and V₅ being equidistant between V₄ and V₆.The method of sizing the disclosed related inventions comprises thesteps of measuring the distance between the midclavicular line and amidaxillary line on the chest of the patient, and selecting apositioning mask size of those inventions based on the measureddistance. This procedure is eliminated by the related application, theabove-identified '125 and '977 patents, and the present invention.

The prior art U.S. Pat. No. 4,583,549 to Manoli and the U.S. Patents toKelly describe precordial electrodes fixed in a preset pattern on aflexible sheet in positions corresponding to the anatomical landmarks onthe patient. The basic problem with all of these inventions is that theyrequire multiple sizes of sensor positioning masks to fit various sizedpersons.

Manoli envisions, without stating any dimensions, three sizes—apediatric, medium adult, and large adult—to fit most children and adultswithin the population. Kelly describes three sizes—small, medium, andlarge adult—to fit most adults within the population. Manoli does notdescribe how one determines which size mask a patient would require.Presumably, under Manoli, a small person requires the smallest of thethree sizes, i.e., the pediatric, and a large person requires thelargest. The invention disclosure is indefinite in this regard.

Thus, Manoli does not describe how to size a patient, and it is commonfor persons placing individual electrodes to make errors. If similarerrors are made when sizing the patient for Manoli's device, it is quitelikely that the wrong size device would be selected. Once a device isapplied to the patient, it would be possible to check the correctness offit. If wrong, however, i.e., the V₆ electrode was located some distancefrom the patient's midaxillary line, the device would have to be removedand replaced by a more appropriate size device. This trial and errorapproach wastes time and materials since the first device would need tobe discarded without ever being used to take an ECG.

The more recent U.S. Pat. No. 5,678,545 to Stratbucker describes anadhesive sheet having a fixed array of individual electrode groupsdisposed at varying locations to provide a “one size fits all” system.One embodiment has twelve precordial electrodes with one electrode eachat V₁, V₂, and V₃ and groups of three electrodes each at V₄, V₅, and V₆,while other embodiments are suggested for groups of electrodes for otherelectrode locations in order to achieve a “one size fits all” system.

Stratbucker describes multiple groupings of electrodes for a “singlesize” system but it is necessary to determine which electrode in eachgroup is within the region of the appropriate location on a patient'schest: for each group of electrodes, there must be a determination ofwhich electrode is closest to the anatomical landmark. Such adetermination is time consuming and would at least be impeded by thefact that palpation will be difficult to perform once the sheet isplaced over a patient's chest. Moreover, each group of electrodesprovides a source for error since there are three electrodes to choosefrom in each group. Assuming one electrode in each group is mostcorrect, the probability of randomly selecting the best electrode fromeach of the groups is 0.33^(X), where X equals the number of groups. Ifthere are three groups of electrodes, as described in one embodimentwhere V₄, V₅, and V₆ consist of groups of three electrodes each, theprobability of randomly selecting the appropriate electrode from eachgroup is 0.037, or 1 out of 27 possibilities. Stratbucker relies on ajudgment determination for each group of electrodes and thereforeselection is time consuming and inexact due to the device physicallycovering the patient's anatomical features.

Although Stratbucker tries to curtail the possibility of placingconventional individual electrodes far from the region of properplacement by confining the decision to simply selecting one electrodeout of each group of three electrodes, medical personnel must stillascertain which electrode is appropriate for each group of electrodes.Not only does this allow for error, it also reduces the chances ofconsistent electrode placement from one test to the next, therebyconfounding any serial comparisons between tests. It also increases thelength of time to administer a resting ECG since a separate decisionmust be made for each group of electrodes.

The inventions of related U.S. Pat. Nos. 6,553,246, 6,006,125 and6,400,977 BI, uniquely solved those problems by providing a multipleprecordial array of sensor electrodes in a single device that will fitessentially three or four classes of sizes of adults and in which sizingis accomplished simply by the determination of the location of a singlesensor which is closest to a selected anatomical landmark. This isachieved by a device having more precordial sensors than the six chestelectrodes needed for the resting ECG but significantly less than thenumber of those taught by Stratbucker.

In the above-identified inventions, some sensors may serve multipleroles to accommodate different patient sizes within one array byutilizing a particular set of sensors. Each set of sensors correspondsto a specific patient size that can be characterized as small, medium,large, or extra large. Once the device of the invention is applied tothe patient, one simply and quickly ascertains which of four V₆ sensorslies on or closest to the patient's midaxillary line and then connectsthe electrode sensor lead wires to the corresponding set of sensors inwhich the V₆ is designated as one of the four selections: small, medium,large, or extra large. The inventions of these patents greatly simplifythe heretofore universal unresolved problem of instantaneous patientsizing during use, while providing the additional benefits of reducingthe cost of production and eliminating the need to stock different sizedevices.

The present invention differs from the related inventions designated inthe related applications portion of this specification to provide adifferent apparatus and method to achieve different results whileutilizing the basic architecture of those inventions. The purpose of therelated inventions is to provide a universal electrocardiogram sensorand positioning device which will fit an accurately estimatedninety-nine percent (99%) of human torso sizes of the adult populationas well as a substantial portion of the teenage population. The presentinvention provides a unique modification to these inventions whereby thesame sensor and positioning device can be utilized for right side chestplacement of sensors as well as standard left side placement forperforming either right chest or left chest ECGs.

It has been determined that it is desirable in certain cases to obtain aright chest ECG, in addition to a left chest ECG, such as, andespecially when discrepancies from normal are discovered in a left chestECG. In such cases, a right chest ECG is often considered desirable butsometimes in the past has been avoided because of the time required torepeat the basic test and the unfamiliarity of technicians for palpatingand properly placing sensors for performing a right chest ECG. Thepurpose of the present invention is to simplify and greatly speed upboth procedures by making a universal sensor mask which, in addition tofitting 99 percent of the chest sizes of adults, and most olderchildren, for left chest ECGs, can also be utilized for right chest ECGsfor the same persons.

SUMMARY OF THE INVENTION

The present invention is a universal ECG multiple sensor dermalprecordial mask for fitting different sizes of human bodies forobtaining electrocardiographic information of either the left or rightside of a human chest using sensors V₁, V₂, V₃, V₄, V₅, and V₆ for leftside recording disposed on one side of the mask and VR₁, VR₂, VR₃, VR₄,V₅, and VR₆ for right side recording disposed on the opposite side ofthe mask. The mask comprises a sheet of non-conductive materialincorporating at least nine sensor positions for the placement of sensorelectrodes forming three sets of sensor groups including three alternatepositions for each V₅ and V₆ (V₅ and VR₆) positions. The nine sensorpositions are disposed in a specific geometric arrangement with theV₁-V₄ (VR₁-VR₄) positions being utilized for all sizes of bodies. The V₅(VR₅) position has two independent sensor positions and shares a thirdwith the V₆ (VR₆) positions, and the V₆ (VR₆) position has twoadditional positions.

The present invention also includes a method for sensor placement forelectrocardio-graphic recording for either the left or the right side ofa human chest by means of a universal ECG multiple sensor dermalprecordial mask for fitting four different sizes of human bodiesincluding extra large. The mask incorporates sensors V₁, V₂, V₃, V₄, V₅,and V₆ for left side recording, and VR₁, VR₂, VR₃, VR₄, VR₅, and VR₆ forright side recording. The method comprises the steps of providing a maskhaving at least ten precordial sensor positions designated on the maskon opposite sides thereof with the V positions disposed on one side andthe VR positions disposed on the other side and forming mirror images ofeach other, said V and VR positions each forming at least four sets ofsensor groups including four alternate sensor positions for each of theV₅ and V₆ (VR₅, and VR₆) sensors. The ten sensor positions are disposedin a specific geometric arrangement with the V₁-V₄ (VR₁-VR₄) sensorpositions being utilized for all sizes of bodies. The V₅ (VR₅) positionhas two independent sensor positions and shares two positions with theV₆ (VR₆) positions, and the V₆ (V₆) position has two additionalpositions. The mask includes indicia for determining which sensorpositions correspond to the four sensor sets. The side of the mask isselected which corresponds to the side of the chest that the ECG isintended to record. The mask is aligned on a patient's chest so that theV₁ and V₂ sensors are disposed approximately on opposite sides of thepatient's sternum. It is then ascertained from the indicia which one ofthe four V₆ sensor positions lies on or is closest to the patient'smidaxillary line, and then electrocardiographic information is obtainedfrom the corresponding set of sensors which include the V₆ sensor.

OBJECTS OF THE INVENTION

It is therefore an important object of the present invention to providea universal ECG multiple sensor positioning device which provides all ofthe sensors for performing an ECG on both the left chest and the rightchest of a human body in a single device.

It is another object of the present invention to provide a universal ECGmultiple sensor positioning device whereby one size fits all includingextra large rather than requiring a multitude of different sizes therebyachieving economic benefits of high volume production and simplifiedsales and distribution.

It is a further object of the present invention to provide a disposableand universal ECG sensor positioning device and method of use in whichless time is needed to perform an ECG since the steps used to determinewhich mask size to utilize and the logistics of maintaining differentsize devices in inventory are eliminated and which can be thrown awayafter use providing less risk of transmitting infection.

It is still another object of the present invention to provide auniversal ECG sensor mask and method of use in which simplified,efficacious, and repeatable sensor placement results on either the leftor right side of a human chest are guaranteed.

It is yet a further object of the present invention to provide a singlemultiple sensor mask and method of use in which a twelve-leadelectrocardiogram which provides the most common means of recordingelectrical activity of the heart to capture changes for either leftchest or right chest ECGs.

It is still another object of the present invention to provide auniversal ECG electrode mask and method of use in which eight differentECGs can be performed by the same device.

And it is still a further object of the present invention to provide auniversal electrocardiogram sensor mask for either left chest or rightchest ECGs which covers ninety-nine percent (99%) of the adult humantorso population including extra large sizes and a large portion of theteenage population.

Other objects and advantages of the present invention will becomeapparent when the method and apparatus of the present invention areconsidered in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of the left chest universal ECG sensor positioningmask of the present invention for three sizes of human torso;

FIG. 2 is a plan view of the opposite side thereof for right chest ECGs;

FIG. 3 is a plan view of the left chest universal ECG sensor positioningmask of the present invention for four sizes of human torso, includingextra large;

FIG. 4 is a plan view of the opposite side thereof for right chest ECGs;and

FIG. 5 is a plan view of a single-sided mask having both right chest andleft chest masks printed thereon.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference is made to the drawings for a description of the preferredembodiment of the present invention wherein like reference numbersrepresent like elements on corresponding views.

FIG. 1 illustrates a plan view of the universal disposable ECG sensorpositioning mask of the present invention for three sizes of human torsofor placement on the left chest of a patient for performing an ECG test.FIG. 2 illustrates a plan view of the opposite side of the universaldisposable ECG sensor positioning mask of FIG. 1 for placement on theright chest of a patient for performing a right chest ECG test. FIG. 3illustrates a plan view of the universal disposable ECG sensorpositioning mask of the present invention for four sizes of human torsoincluding extra large for placement on the left chest of a patient forperforming an ECG test. FIG. 4 illustrates a plan view of the oppositeside of the universal disposable ECG sensor positioning mask of FIG. 3for placement on the right chest of a patient for performing a rightchest ECG test. FIGS. 1-4 illustrate masks which can be printed on theopposite or reverse sides of the mask base layer while FIG. 5illustrates the masks being printed on the same side of the base layerat opposite ends thereof in a pair of wings configuration.

The word “universal” as used in describing the mask is an abbreviationof the descriptive colloquial terminology—one size fits all. The masksof the related inventions fit up to ninety-nine percent (99%) or more ofthe adult population, including overweight and extra large torsopersons, and most older children as well. The term “disposable” meansthat the mask is intended for a single or one time use only. However,the physical form of the mask could be reusable for more than one test,and a more permanent embodiment of the design could be a truly reusablemask possibly requiring sterilization, cleaning, and/or fresh adhesivefor reuse. Therefore, the term “disposable,” as used in the descriptivepreamble of the claims, is provided solely as an aid for most accuratelydescribing the preferred embodiment of the invention in relation to theprior art and should not be interpreted as a limitation on the forms ofthe invention and scope of the claims.

The mask is a dermal chest mask 11 which is formed of a sheet offlexible non-conducting material 13 for carrying or positioning tenchest electrodes or electrodeless sensors 15, or simply holes thereinfor the positioning thereof, for connection by electrical lead wires(not shown) to a standard electrocardiographic diagnostic machine. Thealternate means for sensor placement is designated in the claims hereofby the term “sensor positions” which includes all of the aforementionedand any other means for sensor placement.

The flexible non-conductive web or sheet may be formed from anypreferably transparent natural or synthetic material which is capable ofaccepting a print for the electrical contact areas and the associatedindicia. Generally any cellulosic material, polyester, polyolefin,polyvinyl chloride, nylon or mixtures thereof would be suitable. Cotton,polypropylene, or polyethylene can be used if cost is a consideration.However, polyester is likely the most preferable.

While the most practical form of the invention incorporates the ECGsensors 15 into the flexible sheet 13, a less sophisticated form of theinvention can utilize simply the specific arrangement of sensorpositioning taught herein by the placement of holes for the electrodesin the specific geometric pattern called for herein on the sheet. Thestandard ECG electrodes can then be placed in the holes and adhered tothe patient's skin through the holes. Other masks using the specificsensor positioning arrangement and indicia of the present invention arealso contemplated as within the scope of the invention.

In the prior art, the sensors are printed or secured onto one side ofthe non-conductive web or sheet for the purpose of administratingtypical left chest ECGs. In order to administer a right chest ECG usingthe same mask, the sensors are also printed or secured onto the oppositesides of the web or sheet as will be described more in detailhereinafter.

Detachable limb lead sensors 17 can also easily be provided integral tothe mask during the manufacturing process. In a preferred embodiment,they are formed integral to the mask with a means for easy detachmentsuch as a set of perforations along the line of joinder 19 of the limblead sensor to the mask 11. The ends of the limb lead sensors areprovided with an electrical contact area 21 whereby an electrical leadcan be connected to the sensor by any appropriate means such as anelectrical connector clip.

The receptor sensor electrode positions 15, which are located on themask 11, are spaced relative to each other in a specific geometricconfiguration appropriate for electrocardial recordings from most sizes(FIGS. 1 and 2) to essentially all sizes of adult human torso (FIGS. 3and 4). Each receptor sensor or electrode position is adapted forelectrical connection with the skin of a patient's body for detectingand transmitting electrical signals generated by the patient. Thepreferred embodiment of the mask includes conductor strips 23 each ofwhich extends to and electrically connects to a sensor. The other end ofeach conductor strip terminates in a connector end or terminal whichengages any type of connection or cable junction for electricalconnection with the electrocardiograph analyzer. Separate leads could beutilized for a locator mask which simply provides sensor positions.

Three (FIGS. 1 and 2) or four (FIGS. 3 and 4) discrete electricalcontact or terminal area groups are provided for each left- andright-sided ECGs for connection to an ECG machine to accommodate up tofour different classes of adult human torso sizes: small, medium, large,and extra large. The four individual terminals 25 for V₁ to V₄ arecontiguous, and six discrete terminals 27 are provided for V₅ and V₆ infour sizing configurations. A mask designed for fitting only threeclasses of human torso sizes are described in the related '125 and '977patents. Obviously, a supplier of a mask utilizing the architecture ofthe present invention may choose to provide a mask utilizing less thanall four size choices.

The terminal ends 25, 27 of the conductor strips are preferably disposedadjacent to each other in three (FIGS. 1 and 2) or four (FIGS. 3 and 4)identical paired patterns to facilitate connection to a common connectorwhich can be utilized for either three or four classes of sizes. Acustomized clip is envisioned to simplify use of the mask of the presentinvention by permitting a single-clip connection. Pin locator cut-outs29 and indicia 31 for the clip allow it to be selectively engaged to themask for connecting a certain or selected set of six sensors to the ECGmachine.

In a preferred embodiment of the invention, where the sensors and leadsare formed integral to the mask, means are required to enable thesensors. In order to establish electrical connection between a humanbody and the receptor sensor positions 15, a biocompatible electricallyconductive adhesive, such as hydrogel, is applied to the body contactingsides of the sheet at each sensor site for adhesion to the skin of thepatient. The adhesive is generally transparent and shown in outline 16in the drawings. Hydrogel is commercially available as are othersuitable conductive adhesives and any suitable electrodermal adhesivewould serve the purpose. The size of the adhesive area is generallybetween 3 and 9 square centimeters. When the mask is pressed against theskin of the patient's chest, the sensors are electrically connected tothe patient at each receptor.

The gel-coated adhesive area of the mask 11 includes at least onerelease liner in releasable adhesive contact with the gel covering thesensors 15. Because the release liner can be transparent, and is simplya sheet of material, it is not shown in the drawings. Separate releaseliners could be provided for each sensor, but in the preferredembodiment, a single release liner covers all of the sensors associatedwith a left-side ECG and a second release liner covers all the sensorsassociated with a right-side ECG. The mask can be removed from the linerin a single operation to expose all of the sensors as a unit (except forthe limb lead sensors). The limb lead sensors 17 are releasedindividually having been separated at the perforations 19 along the lineof joinder with the mask. The flexible release liner covering thereceptors may be made from a suitable dielectric film or coated paperwhich includes polypropylenes, polyesters, olefinic polymers, polyvinylchloride and its copolymers, acrylic rubbers, ABS resin, and the like.Commercial suppliers for these materials are listed in the relatedpatents.

The receptor electrodes 15 and the conductor strips 23 can be producedfrom any electrically conductive material, e.g., metal, foils,conductive polymers, graphite, carbon fibers, and the like. They includegold, copper, silver, tin, aluminum, N-vinyl pyrrolidone, and alloys ormixtures thereof. The receptor/conductors can also be made from aconductive paste of a metal in particle form in a suitable binder whichis printed or silk screened onto the flexible non-conductive sheet orelectrolessly deposited. A connective polymer may be heat pressed orotherwise conventionally secured to the web or sheet.

Copper strips could be utilized and electrolessly deposited on thepolymeric sheets in a range of thickness from about 0.25 to about 5microns, more preferably from 0.25 to 1.5 microns, and most preferably0.4 microns in thickness. A metallic ink may be preferable such as acommercially available silver ink. Each of the conductor strips are lessthan 10, and preferably less than 5, micrometers in thickness, wherebythe flexibility of the connector and adhesion of the gel surface to theskin are substantially enhanced.

The exposed conductive strips 23 may be partially covered with adielectric layer for insulating the conductive pathways. This coatingcan be transparent and is also shown in the drawings in outline 24. Thestrips are coated with a dielectric polymeric material in such a way sothat only selective portions comprising the sensor 15 and the electricalcontact or terminal areas 25, 27 are exposed. Suitable dielectriccoatings include polyesters, ethylene-vinyl acetate copolymers,polyvinyl chloride and its copolymers, terpolymers such asacrylonitrile-butadiene styrene (ABS resins) and inter alia.

Therefore, a preferred laminate for the flexible sheet of the inventioncan comprise several layers, several of which can be transparent. Apreferred embodiment of the invention would include: (1) a base layer ofa flexible non-conductive film of polyethylene terphthalate; (2) a bondlayer for the conductor strips such as a catalyst in contact with aconductive ink; (3) a conductor strip comprised of silver ink; (4) anadhesive layer such as hydrogel superimposed upon the silver ink in thesensor areas of the mask, or alternatively, a dielectric layersuperimposed upon the silver ink in the conductor strip area of themask; and (5) a flexible release liner as the top layer superimposedupon at least the adhesive layer of the mask.

In order to utilize the mask of the present invention to take rightchest ECGs, a mirror image of the mask for left chest ECGs must beprovided on opposite sides thereof. This is effected in either of twoways: first, by turning the mask over and printing the identical bondlayer, conductor strips, and adhesive layers on the opposing side of themask in an identical overlay which creates the mirror image of theopposite or left chest side. It is then covered with a flexible releaseliner as the top layer. As a result, two separate masks are provided onopposite sides of the base layer covered by separate release liners butonly one is utilized depending upon which side of the mask from whichthe release liner is selectively removed. The second way is by printingboth masks on the same side of the base layer extending in oppositedirections from the center of the mask in a spread wings configurationwhereby the left and right chest masks are disposed at opposite ends ofthe same side of the mask. In the design shown in FIG. 5, separateelectrical connectors are required for the left and right chest masksunless the electrical conductor printing is rerouted to provide terminalarea groups which can be engaged by a universal design electricalconnector which will accommodate both right and left chest ECGrecordings. An alternative design for FIG. 5 could over lay V1/VR2 andVR1/V2 with the electrical printing using a common connector.

Since the mask of the present invention is designed for use by untrainedpersonnel as well as a trained individual, the sheet material of themask contains designator markings or indicia to simplify attaching to orpositioning of the mask on the patient's chest. It is sufficientlyself-describing such that it allows a person untrained inelectrocardiography to position the mask to obtain highly reliable andrepeatable ECG signals for either left or right chest ECGs. It alsoincludes indicia for sizing the patient.

FIG. 1 shows the nine-sensor array for left chest ECGs which includessingular V₁, V₂, V₃, and V₄ sensor positions and three alternate V₅ andV₆ sensor positions. The V₅ and V₆ positions each have two independentsensor positions (V_(5S), V_(5M), V_(6M), and V_(6L)) and share a thirdposition (V_(5L)/V_(6S)). FIG. 1 also shows the indicia therefor.Indicia V1, V2, V3, and V4 indicate a single position for each of theV₁, V₂, V₃, and V₄ sensors. Indicia V5S indicates V₅ small; V5Mindicates V₅ medium, V5L/V6S indicates either V₅ large or V₆ small. V6Lcorrelates to V₆ large. The S, M, and L indicia are provided to aid inselecting which set of sensors are to be utilized. The additionalindicia between V1 and V2, and V6M and V6L, aid the user in positioningthe mask. The indicia 31 proximate the pin locator cut-outs 29 aid inselecting the electrical connection for sensor set selection.

FIG. 2 shows the nine-sensor array for right chest ECGs which are themirror image of the left chest array. The indicia are the same anddifferentiated from the left chest indicia by an additional Rdesignation. The array includes, like the left chest array, singularVR₁, VR₂, VR₃, and VR₄ sensor positions and three alternate V₅ and VR₆sensor positions. The V₅ and VR₆ positions each have two independentsensor positions (VR_(5S), VR_(5M), VR_(6M), and VR_(6L)) and share athird position (VR_(5L)/VR_(6S)). FIG. 2 also shows the indiciatherefor. Indicia VR1, VR2, VR3, and VR4 indicate a single position foreach of the VR₁, VR₂, VR₃, and VR₄ sensors. Indicia VR5S indicates VR₅small; VR5M indicates V₅ medium, VR5L/VR6S indicates either VR₅ large orVR₆ small. VR6L correlates to VR₆ large.

FIG. 3 shows the ten-sensor array for left chest ECGs which includessingular V₁, V₂, V₃, and V₄ sensor positions and four alternate V₅ andV₆ sensor positions. The V₅ and V₆ positions each have two independentsensor positions (V_(5S), V_(5M), V_(6L), and V_(6XL)) and share twopositions (V_(5L)/V_(6S) and V_(5XL)/V_(6M)). FIG. 3 also shows theindicia therefor. Indicia V1, V2, V3, and V4 indicate a single positionfor each of the V₁, V₂, V₃, and V₄ sensors. Indicia V5S indicates V₅small; V5M indicates V₅ medium, V5L/V6S indicates either V₅ large or V₆small. V5XL/V6M indicates either V₅ extra large or V₆ medium. V6L andV6XL correlate to V₆ large and extra large, respectively.

FIG. 4 shows the ten-sensor array for right chest ECGs which are themirror image of the left chest array. The indicia are the same anddifferentiated from the left chest indicia by an additional Rdesignation. The array includes, like the left chest array, singularVR₁, VR₂, VR₃, and VR₄ sensor positions and four alternate V₅ and VR₆sensor positions. The VR₅ and VR₆ positions each have two independentsensor positions (VR_(5S), VR_(5M), VR_(6L), and VR_(6XL)) and share twopositions (VR_(5L)/VR_(6S) and VR_(5XL)/VR_(6M)). FIG. 4 also shows theindicia therefor. Indicia VR1, VR2, VR3, and VR4 indicate a singleposition for each of the VR₁, VR₂, VR₃, and VR₄ sensors. Indicia VR5Sindicates VR₅ small; VR5M indicates V₅ medium, VR5L/VR6S indicateseither VR₅ large or VR₆ small. VR5XL/VR6M indicates either VR₅ extralarge or VR₆ medium. VR6L and VR6XL correlate to VR₆ large and extralarge, respectively. The S, M, L, and XL indicia are provided to aid inselecting which set of sensors are to be utilized. The additionalindicia between VR1 and VR2, and VR6M and VR6L, aid the user inpositioning the mask.

FIGS. 1-4 are illustrations of sensor array masks which are printed onone side of a base layer sheet. The right chest masks and the left chestmasks can be printed on the opposite or reverse sides of the same baselayer or, as shown in FIG. 5, on opposite sides or the opposed ends ofthe same side of the base layer. In other words, the definition of theterm “opposite sides” as used in the claims means either the reversesides of the same sheet or opposing sides or ends of the same side of asheet. When the masks are printed on both sides of a base layer, oneside includes the V (left) sensor positions and the reverse sideincludes the VR (right) sensor positions. When the masks are printed onthe same side of the base layer, one half or end includes the V (left)sensor positions and the opposed or other end includes the VR (right)sensor positions.

In the following description of the present invention and in the claimsappended hereto, the opposite mirror image sides of the mask can bedescribed concurrently. Each time a left chest sensor position orindicia is mentioned, the corresponding right chest designator followsin parentheses so that both sides are described concurrently. The sameis true for the value designators for distance and angularity associatedwith the sensor positions where they are differentiated.

Nine or ten sensors 15 are arranged in a precordial sensor array ofthree or four sets of six sensors each in which certain of the sensorsserve the same function in each of the three or four size sets of six,and at least one of the sensors serves as different designated sensorsin the four different sets. If only three different sizes are providedon the mask, only nine precordial sensors need be provided as shown inFIGS. 1 and 2. In order to accommodate an extra large size chest, a setof ten precordial sensors are required as shown in FIGS. 3 and 4. FIG. 5shows the FIGS. 1 and 2 for a three-sizes mask in a wings configurationwith both the left chest and right chest masks on the same side of thebase layer. The mask for fitting four sizes of persons as illustrated inFIGS. 3 and 4 would be identical except expanded to include theadditional sensor positions and applicable indicia.

The nine or ten precordial sensors are disposed in a specific universalgeometric arrangement rather than in predetermined fixed arrays ofindividual classes of sizes of sensor groups, as taught in the relatedcases and the Kelly and Manoli patents, or in multiple all-inclusivesensor group arrays as taught by the Stratbucker singular patent. Norare they positionable in an arbitrary individually located array of sixprecordial sensors as would be placed by a technician for a resting ECG.In the present invention, nine sensors form three sets of sensor groupsincluding three positions for each of the V₅ and V₆ (VR₅ and VR₆)positions in which one sensor position serves for either V₅ or V₆ (VR₅or VR₆) in two different sensor sets whereby three sets of six sensorseach are provided by the nine sensors to position six of the sensorsproximate to the anatomical landmarks of three different classes ofhuman torso sizes.

Ten sensors form four sets of sensor groups including four positions foreach of the V₅ and V₆ (VR₅ and VR₆) positions in which two sensorpositions serve for either V₅ or V₆ (VR₅ and VR₆) in four differentsensor sets whereby four sets of six sensors each are provided by theten sensors to position six of the sensors proximate to the anatomicallandmarks of four different classes of human torso sizes including extralarge.

The sensor positions 15 are disposed on the flexible sheet 13 which isdesigned to adhere to a human torso so that the receptor sensors arelocated upon the precordial area of the chest and above the epigastricregion of the abdomen. The flexible sheet can be essentially transparentexcept where it underlies the indicia. In those areas, it probably needsto be opaque so that the different indicia on opposite sides of thesheet are clearly legible.

The mask includes the self-explanatory indicia 33, 35 for determining ifit is for left chest or right chest use and for aligning it on both thecenterline of the patient's sternum and on the fourth intercostal space,respectively, whereby at least three or four sets of sensor positions onthe mask, comprising six sensors each, can accommodate up to three orfour different classes of human torso sizes, respectively, for eitherleft chest or right chest ECGs. In addition to facilitating correctplacement of the receptors on the precordial areas of the human torso,the indicia also provide for selecting the correct set of sensorpositions for the torso size and show which sensors are to be used.Indicia 29, 31 for the electrical connections to the ECG machine arealso essentially self-explanatory and are accordingly based on theselected torso size of the patient. The precordial indicia indicatewhich sets of sensors correlate to which torso size and that two of thesensors are shared or utilized for four classes of torso sizes butnumbered as different designation sensor positions, V₅ (VR₅) or V₆(VR₆).

When the electrodermal connectors are properly positioned for attachmentto a patient, the position of the receptors at V₁ (VR₁) and V₂ (VR₂) aredisposed to lie approximately on opposite sides of the patient's sternumat the fourth intercostal space as shown by the indicia 33, 35. Thereceptors at V₃ (VR₃) and V₄ VR₄) are attached over the ribs, with V₃(VR₃) positioned approximately equidistant between V₂ (VR₂) and V₄(VR₄), and with V₄ (VR₄) positioned approximately over the intersect ofthe fifth intercostal space and the left midclavicular line. Thereceptors at V₅ (VR₅) and V₆ (VR₆) are placed at the side of the torsoso that V₅ is substantially midway between V₄ (VR₄) and V₆ (VR₆).

In positioning the array of receptors for the preferred embodiment ofthe present invention, it has been found that the distance between V₁,V₂, V₃, and V₄ (VR₁, VR₂, VR₃, and VR₄) can be consistent for all sizesof human torsos. The dimensions between V₁, V₂, V₃, and V₄ (VR₁, VR₂,VR₃, and VR₄) have been developed to accommodate nearly all adultswithin tolerances acceptable for the resting ECG. It has also been foundthat body placement for receptors V₅ and V₆ (V₅ and VR₆) vary dependingon individual size. These variations are uniquely accommodated in onesize mask by the present invention.

There is a novel method provided by the present invention fordetermining the proper size selection of electrode sets, i.e., forselecting six of the ten sensor positions for performing an ECGdepending upon the torso size of the patient. The selection of the sixsensors is ascertained by determining which one of the same designationsensor positions in each set lies closest to a selected precordiallandmark whereby the set containing that closest lying position isselected as the set of six sensors to be utilized. As with V₁-V₄(VR₁-VR₄), it has been determined that the distance from the V₄ (VR₄)sensor position to the V₆ (VR₆) sensor position determines the size of apatient. For the inventions disclosed in the prior related applications,the measurement of this distance is determined by having the applyingtechnician measure, such as by using his/her thumb and the middlefinger, the distance between the midclavicular line and the midaxillaryline on the chest of the patient. This distance is then compared to asizing scale to select the proper size of mask. The present invention,however, does not require any type of intermediate step to determine apatient's size. Rather, the mask is applied to the patient and a simplevisual observation ascertains which of four V₆ (VR₆) sensors liesclosest to the patient's midaxillary line to establish that patient'ssize and the selection of the corresponding sensor set.

The distance between V₄ to V₆ (VR₄ to VR₆), that is, the distancebetween the midclavicular line and the midaxillary line on the patient,varies within predetermined limits based on the size of the torso. For asmall size, the distance between V₄ and V₆ (VR₄ to VR₆) can range fromabout 2.5 to 4.5 inches; for the medium size, the distance can rangefrom about 4.0 to 6.0 inches; for the large size, the distance can rangefrom about 6.0 to 8.0 inches; and, for the extra large size, thedistance can range from 8.0 to 12.0 inches.

In the present invention, sensors V₁, V₂, V₃, and V₄ (VR₁, VR₂, VR₃, andVR₄) are positioned the same for all sizes of torsos. The center of V₁(VR₁) is located on a point generally about 2.0 inches from the centerof V₂ (VR₂) approximately on the 270 (90 for VR₁) degree radial from thecenter of V₂ (VR₂) wherein the radial is measured with zero degreesmeasured from north at the top of V₂ (VR₂). The center of V₄ (VR₄) islocated on a point generally 3.5 inches from the center of V₂ (VR₂)approximately on the 125 (235 for VR₄) degree radial from the center ofV₂ (VR₂). The center of V₃ (VR₃) is in line with V₂ and V₄ (VR₂ and VR₄)and is located on a point substantially between the center of V₂ (VR₂)and the center of V₄ (VR₄). The receptors V₅ and V₆ (VR₅ and VR₆) havefour alternative positions each: all of the positions being disposed onthe 90 degree radial from V₄ (270 degree radial from VR₄). The centersof the V₅ (VR₅) positions are located approximately 1.75, 2.5, 3.5, and5.0 inches from V₄ (VR₄) and the centers of the V₆ (VR₆) positions arelocated approximately 3.5, 5.0, 7.0, and 10.0 inches from V₄ (VR₄)whereby the centers of both V₅ and V₆ (VR₅ and VR₆) which are bothlocated approximately 3.5 and 5.0 inches from V₄ (VR₄) share a commonsensor in different sets of sensors.

If the mask is single-sided for right chest ECGs only, then the sensorposition V designations may not carry the VR indicia but simply the Vindicia as for left chest masks. However, the two angular dispositionsof V₂ and V₄ sensor position are decreased by 180 degrees and increasedby 110 degrees, respectively. In other words, for a right chest mask thecenter of V₁ is located on a point generally about 2.0 inches from thecenter of V₂ approximately on the 90 degree radial from the center of V₂wherein the radial is measured with zero degrees measured from north atthe top of V₂. The center of V₄ is located on a point generally 3.5inches from the center of V₂ approximately on the 235 degree radial fromthe center of V₂. The receptors V₅ and V₆ have four alternativepositions disposed on the 270 degree radial from V₄. The distancesbetween the sensor positions are the same as for the left chest masks.

The table below corresponds to the determined measurements for electrodeplacement which are all inherent in the present invention. It shows thepreferred dimensional layout for V₅ and V₆ (VR₅ and VR₆) relative to V₄(VR₄) for different sized torsos. Obviously, small variations in thelengths of the measurements are within the scope of the invention:

TABLE I V₄-V₅ V₅-V₆ V₄-V₆ Size VR₄-VR₅ VR₅-VR₆ VR₄-VR₆ Small 1.75″ 1.75″3.5″ Medium 2.5″ 2.5″ 5.0″ Large 3.5″ 3.5″ 7.0″ X-Large 5.0″ 5.0″ 10.0″

The distance between V₁ and V₂ (VR₁ and VR₂) is 2.0 inches, the distancebetween sternum centerline and V₄ (VR₄), along a horizontal line is 3.85inches, and the distance between V₂ and V₄ (VR₂ and VR₄) along avertical line is 2.0 inches, although this vertical distance could be upto 3.5 inches without considerably altering the effectiveness of themask. In addition, V₃ (VR₃) is located on a diagonal line between V₂ andV₄ (VR₂ and VR₄), and is equidistant from V₂ and V₄ (VR₂ and VR₄). Thesevariations can be combined to create a universal mask by the use of onlyten sensors to accommodate practically all adult sizes of torso.

The mask of the present invention provides a plurality of connectors orterminals arranged in a predetermined dimensional array V₁-V₆ (VR₁-VR₆)on the flexible sheet which inherently observes the dimensions dictatedby Table I. In providing alternative locations of the sensors, thedimensional array on the flexible sheet becomes universal and thespecific size configuration of the dimensional array or layout on theflexible sheet is determined in the same maimer as for multiple sizes ofmasks to permit the production of an accurate electrocardial recordingduring ECG testing which can be reliably repeated.

The nine or ten sensors are positioned on the sheet in a geometricpattern approximating the standard precordial anatomical landmarks ofany adult human being. The positioning of sensors V₁-V₄ (VR₁-VR₄) is thesame for all sizes of torsos and is shown in FIGS. 1 to 4 as V1, V2, V3,and V4 (VR1, VR2, VR3, and VR4). The V₅ and V₆ (VR₅ and VR₆) positionseach have three or four alternate positions including two independentsensor positions each: V5S and V5M (VR5S and VR5M) for V₅ (VR₅) in boththe three and four sensor set masks, and V6M and V6L (VR6M and VR6L) inthe three set mask, and V6L and V6XL (VR6L and VR6XL) in the four sensorset mask for V₆ (VR₆). They also have one or two shared positions:V5L/V6S (VR5L/VR6S) for both the three and four sensor set masks andV5XL/V6M (VR5XL/VR6M) for the four sensor set mask. All of the V₅ and V₆(VR₅ and VR₆) sensor positions lie along the same line with, and arespaced from, the V₄ (VR₄) sensor.

When the mask is utilized for a small size torso, the first independentV₅ (VR₅) alternate sensor position V5S (VR5S), disposed closest to theV₄ (VR₄) sensor position V4 (VR4), is utilized along with a first sharedV₅ and V₆ (VR₅ and VR₆) alternate sensor position V5L/V6S (VR5L/VR6S)which of the V₆ (VR₆) positions is also disposed closest to the V₄ (VR₄)position.

When the mask is utilized for a medium size torso, the secondindependent V₅ (VR₅) alternate sensor position V5M (VR5M) is utilizedalong with the V6M (VR6M) position in the three sensor set mask or thesecond shared V₅ and V₆ (VR₅ and VR₆) alternate sensor position V5XL/V6M(VR5XL/VR6M) position in the four sensor set mask.

When the mask is utilized for a large size torso, the first shared V₅and V₆ (VR₅ and VR₆) alternate sensor position V5L/V6S (VR5L/VR6S) isutilized along with the first independent V₆ (VR₆) alternate sensorposition V6L (VR6L).

When the mask is utilized for an extra large size torso, the secondshared V₅ and V₆ (VR₅ and VR₆) alternate sensor position V5XL/V6M(VRXL/VR6M) is utilized along with the second independent V₆ (VR₆)alternate sensor position disposed furthest from the V₄ (VR₄) sensorposition.

The first and second shared V₅ and V₆ (VR₅ and VR₆) sensor positionsfunction either as the V₅ or V₆ (VR₅ or VR₆) positions depending uponthe size of torso the sensor mask is being utilized on. When the mask isutilized for a small and large-size torsos, the first shared V₅-V₆(VR₅-VR₆) position functions as V₆ or V₅ (VR₆ or VR₆), respectively.When the mask is utilized for a medium and extra large-size torso, thesecond shared V₅-V₆ (VR₅-VR₆) position functions as V₆ or V₅ (VR₆ orVR₅), respectively.

The sensor set selected for performing the ECG on a specific patient isrecorded for the taking of subsequent ECGs on that patient to insurerepeatability of sensor placement.

The present invention also contemplates a method for sensor placementfor performing electrocardiographic recording, and a method of sensorplacement for performing twelve-lead electrocardiograms on either theleft chest or the right chest, by means of a universal ECG multiplesensor dermal precordial mask incorporating sensors V₁, V₂, V₃, V₄, V₅,and V₆ (VR₁, VR₂, VR₃, VR₄, VR₅, and VR₆). The mask is formed forfitting or accommodating up to four different sizes of human bodiesincluding extra large with repeatability and clinical efficacy of sensorpositions V₁, V₂, V₃, V₄, V₅, and V₆ (VR₁, VR₂, VR₃, VR₄, V₅, and VR₆)placement irrespective of the varying human body torso sizes and thedifferent distances between the human body anatomical landmarks.

The method of sensor placement is comprised of several steps. A mask isprovided which is formed for clinically efficacious placement of sixprecordial sensors on a patient's chest irrespective of torso size. Themask has a multiplicity of precordial sensor positions disposed in aspecific geometrical pattern rather than in predetermined fixed arraysof individual sensor groups or an arbitrary individually located arrayof six precordial sensors. As few as nine sensors can be utilized toserve as sensors for at least three different classes of human torsosizes. The addition of only one sensor position permits the mask toaccommodate four different classes of human torso sizes including extralarge.

In the preferred method of the invention, the mask is provided with anarrangement of at least nine precordial sensor positions which arearranged in or form at least three sets of sensor groups of six sensorseach. Certain of the sensor positions serve the same function in each ofthe sets, and at least one of the sensors serves as a differentdesignated sensor in different sets. In the preferred embodiment of theinvention, ten precordial sensor positions are provided which aredisposed on opposite sides of the mask in a specific geometric mirrorimage arrangement forming four sets of sensor groups with the V and VRpositions disposed on opposite sides of the mask. Each side includesfour alternate sensor positions for each of the V and VR sensorpositions. The V₁-V₄ (VR₁-VR₄) positions are utilized for all four sizesof bodies. In all four groups, two sensor positions serve for either V₅or V₆ (VR₅ or VR₆) in the four different sensor sets whereby four setsof six sensor positions each are provided by the ten sensor positions tolocate six of the sensors proximate the standard precordial anatomicallandmarks of four different classes of sizes of human torsos.

The ten sensor positions are disposed on opposite sides of the maskforming four sets of sensor groups including three alternate positionsfor each of V₅ and V₆ (V₅ and VR₆) in which two sensor positions servefor either V₅ or V₆ (VR₅ or VR₆) in four different sensor sets wherebyfour sets of six sensors each are provided by the ten sensor positionsto position six of the sensors proximate to the anatomical landmarks offour different classes of sizes of human torsos.

The mask is provided with indicia for determining whether it is for leftchest or right chest use and for positioning it on a patient's sternumcenterline and the fourth intercostal space and for determining whichsensor positions correspond to the four sensor sets.

The mask applicator selects which side of the mask corresponds to theside of the patient's chest that the ECG is intended to record. Themasks which have sensors printed on both sides thereof cover one side ofthe chest, and when the mask is utilized for a left chest ECG recordingone side of the mask is utilized, and when the mask is utilized for aright chest ECG recording the reverse side of the mask is utilized. Themasks which have sensor positions printed on one side thereof cover thewhole chest, and when the mask is utilized for a left chest ECGrecording one half of the mask is utilized, and when the mask isutilized for a right chest ECG recording the other half of the mask isutilized.

The mask is placed on a patient's chest and the positioning indicia onthe mask are aligned with the corresponding anatomical positions on thepatient's chest so that V₁ and V₂ (VR₁ and VR₂) are disposedapproximately on opposite sides of the patient's sternum at the fourthintercostal space. Six of the ten sensor positions are then selected forperforming an ECG depending upon the torso size of the patient bydetermining which one of the same designation sensors in each set liesclosest to a selected precordial landmark whereby the set of sensorscontaining the closest lying sensor is selected as the set of six sensorpositions to be utilized. In the preferred embodiment of the invention,this is done by ascertaining from the mask's indicia which of the fourV₆ (VR₆) sensor positions lies on or closest to the patient'smidaxillary line.

Sensor leads from ECG test apparatus are connected to the correspondingset of sensors which include the identified V₆ (VR₆) position, andelectrocardiographic information is obtained from those sensors.

Thus, in summary, both an apparatus and methods for torso sizing andsensor placement for performing twelve-lead electrocardiograms foreither left chest or right chest recording are provided, and the statedobjects of the present invention are achieved. A single mask design,having only ten sensors on either side of the mask, instead of three orfour different sizes of masks, as taught by the prior art, provides auniversal size which can be utilized to obtain the benefits ofsimplified high volume production in order to lower the cost to the userand reduce the time previously needed to establish the size of apatient. The preferred embodiment of the present invention solves theproblems associated with high variability of individual sensor placementwhich may produce inaccurate ECGs, and thus an incorrect diagnosis, andwhich problems prevent valid and reliable serial comparisons betweenrepeat ECGs on the same patient.

The present invention eliminates the logistics of maintaining differentsize sensor masks and left and right chest inventories. This includesthe stock in the central supply of a hospital, stock rooms of wards andclinics, and individual ECG carts. A related benefit is that stock wouldbe depleted evenly thereby eliminating the possibility that some stock,e.g., a less often used size in a four-size system, might not be usedprior to reaching an expiration date. The one size design of the presentinvention eliminates the steps required to determine a patient's torsosize and fits ninety-nine percent (99%) of both the left and right sidesof the chest of the adult torso population including extra large. Anypossibility of error when sizing a patient is eliminated.

The method of the present invention is one in which there is less wastesince essentially all adult patients and teenagers are accommodated bythe one mask. With more than one mask size, there is the possibilitythat a wrong size would be applied to a patient and would need to beremoved and discarded prior to applying the correct size mask. Thistrial and error situation would also increase the time spent performingan ECG on one patient. This is eliminated by the present invention.

The mask and method of use of the present invention in which theadditional sensors with their respective adhesive areas increase thetotal area adhered to the patient. This will reduce the tension on eachindividual sensor since any pulling caused by respiration or from theECG cable assembly will be shared by a greater number of sensors thanwould exist with a six-sensor precordial pad. It is generally understoodthat too much tension on a sensor decreases its performance.

It is also an object of the present invention to permit the taking offour different ECGs simultaneously with the same mask on either the leftor right chest. Because the mask contains four precordial sensorpatterns, it is possible to take four different ECGs by connecting toeach pattern in turn by simply reapplying the single six-conductorconnectors serially to the four terminal sets. This may provideadditional diagnostic information beyond what is now obtained from aconventional ECG using six precordial sensors.

Thus, it will be apparent from the foregoing description of theinvention in its preferred form that it will fulfill all the objects andadvantages attributable thereto. While it is illustrated and describedin considerable detail herein, the invention is not to be limited tosuch details as have been set forth except as may be necessitated by theappended claims.

1. A method for sensor placement for performing electrocardiographicrecording of either the left or the right side of a human chest by meansof a universal ECG multiple sensor dermal precordial mask for fittingfour different sizes of human bodies including extra large, said maskincorporating sensor positions V₁, V₂, V₃, V₄, V₅, and V₆ for left siderecording, and VR₁, VR₂, VR₃, VR₄, VR₅, and VR₆ for right siderecording, said method comprising the steps of providing a mask havingat least ten precordial sensor positions designated on said mask onopposite sides thereof with the V positions disposed on one side and theVR positions disposed on the other side and forming mirror images ofeach other, said V and VR positions each forming at least four sets ofsensor groups including three alternate sensor positions for each ofsaid V₅ and V₆ (VR₅ and VR₆) positions, wherein said ten sensorpositions are disposed in a specific geometric arrangement with saidV₁-V₄ (VR₁-VR₄) positions being utilized for all sizes of bodies, saidV₅ (VR₅) position having two independent sensor positions and sharingtwo positions with said V₆ (VR₆) positions, and said V₆ (VR₆) positionhaving two additional positions, said mask including indicia fordetermining which V₅ and V₆ (VR₅ and VR₆) sensor positions correspond tosaid four sensor groups, selecting which side of said mask correspondsto the side of the chest the ECG is intended to record, aligning saidmask on a patient's chest so that said V₁ and V₂ (VR₁ and VR₂) positionsare disposed approximately on opposite sides of the patient's sternum atthe fourth intercostal space, ascertaining from said indicia which oneof the four V₆ (VR₆) sensor positions provided by said mask lies on oris closest to the patient's midaxillary line, and utilizing for saidrecording the corresponding set of sensor positions which include theascertained V₆ (VR₆) position.
 2. The method of claim 1 wherein saidmask has sensors printed on both sides thereof and covers one side ofthe chest, and when said mask is utilized for a left chest ECG recordingone side of the mask is utilized, and when said mask is utilized for aright chest ECG recording the reverse side of said mask is utilized. 3.The method of claim 1 wherein said mask has sensor positions printed onone side thereof and covers the whole chest, and when said mask isutilized for a left chest ECG recording one half of the mask isutilized, and when said mask is utilized for a right chest ECG recordingthe other half of said mask is utilized.
 4. A method of sensor placementfor performing twelve lead electrocardiograms on either the left chestside or right chest side of four different sizes of adult human bodiesincluding extra large by means of a universal ECG multiple sensor dermalchest mask with repeatability and clinical efficacy of either left orright sensors V₁, V₂, V₃, V₄, V₅, and V₆ (VR₁, VR₂, VR₃, VR₄, V₅, andVR₆) placement irrespective of the varying human body torso sizes andthe different distances between the human body anatomical landmarks,said method of sensor placement comprising the steps of providing a maskhaving at least ten precordial sensors disposed on opposite sidesthereof with the V positions disposed on one side and the VR positionsdisposed on the other side and forming mirror images of each other, saidV and VR positions each forming at least four sets of sensor groupsincluding three alternate sensor positions for each of said V₅ and V₆(VR₅ and VR₆) positions, wherein said ten sensor positions are disposedin a specific geometric arrangement rather than in predetermined fixedarrays of individual sensor groups or an arbitrary individually locatedarray of six precordial sensors needed for a resting ECG, saidarrangement of ten sensor positions on opposite sides of said maskforming said four sets of sensor groups including three alternatepositions for each of said V₅ and V₆ (VR₅ and VR₆) in which two sensorpositions serve for either V₅ or V₆ (VR₅ or VR₆) in four differentsensor sets whereby four sets of six sensors each are provided by saidten sensor positions to position six of said sensors proximate to theanatomical landmarks of four different classes of sizes of human torsos,said mask including first indicia for positioning said mask on apatient's sternum centerline and the fourth intercostal space and secondindicia for determining which sensors correspond to said four sensorsets, selecting which side of said mask corresponds to the side of thechest the ECG is intended to record, placing said mask on a patient'schest and aligning said first positioning indicia on said mask with saidpatient's corresponding anatomy, ascertaining from said second indiciawhich of the four V₆ (VR₆) sensor positions lies on or closest to thepatient's midaxillary line, and connecting sensor lead wires from ECGtest apparatus to the corresponding set of sensors which include saidclosest midaxillary V₆ (VR₆) sensor.
 5. The method of claim 4 whereinsaid mask has sensors printed on both sides thereof and covers one sideof the chest, and when said mask is utilized for a left chest ECGrecording one side of the mask is utilized, and when said mask isutilized for a right chest ECG recording the reverse side of said maskis utilized.
 6. The method of claim 4 wherein said mask has sensorpositions printed on one side thereof and covers the whole chest, andwhen said mask is utilized for a left chest ECG recording one half ofthe mask is utilized, and when said mask is utilized for a right chestECG recording the other half of said mask is utilized.
 7. A universalECG multiple sensor dermal precordial mask for fitting three differentsizes of human bodies for electrocardiographic recording of either theleft or the right side of a human chest using sensors V₁, V₂, V₃, V₄,V₅, and V₆ for the left side recording disposed on one side of saidmask, and VR₁, VR₂, VR₃, VR₄, VR₅, and VR₆ for right side recordingdisposed on the opposite side of said mask, said mask comprising a sheetof non-conductive material incorporating at least nine sensor positionsfor the placement of sensor electrodes forming three sets of sensorgroups including three alternate positions for each of the V₅ and V₆(VR₅ and VR₆) positions, said nine sensor positions being disposed in aspecific geometric arrangement with said V₁-V₄ (VR₁-VR₄) positions beingutilized for all sizes of bodies, said V₅ and V₆ (VR₅, and VR₆)positions each having two independent sensor positions and sharing athird.
 8. The mask as set forth in claim 7 wherein said sensors areprinted on both sides of said mask with one side including said Vsensors and the reverse side including said VR sensors.
 9. The mask asset forth in claim 7 wherein said sensors are printed on the same sideof said mask with one half side thereof including said V sensors and theother half side thereof including said VR sensors.
 10. A mask as setforth in claims 8 or 9 wherein said sheet is flexible and disposable.11. A mask as set forth in claims 8 or 9 wherein said sheet is flexibleand disposable.
 12. The mask as set forth in claim 7 wherein said V₁ andV₂ (VR₁ and VR₂) sensor positions are disposed equidistant from thepatient's sternum, the center of said V₁ (VR₁) position is locatedapproximately 2.0 inches from the center of said V₂ (VR₂) position onthe 270 (90) degree radial therefrom, the center of said V₄ (VR₄)position is located approximately 3.5 inches from the center of said V₂(VR₂) position on the 125 (235) degree radial therefrom, the center ofsaid V₄ (VR₄) position is located on a line and equidistant between saidV₂ (VR₂) and said V₄ (VR₄) positions, and said V₅ and V₆ (VR₅ and VR₆)positions have three alternative positions each, all of said positionsbeing disposed on a 90 (270) degree radial from said V₄ (VR₄) position,the centers of said V₅ (VR₅) positions being located 1.75, 2.5, and 3.5inches therefrom and the centers of said V₆ (VR₆) positions beinglocated 3.5, 5.0, and 7.0 inches therefrom whereby the centers of saidV₅ and V₆ (VR₅ and VR₆) positions which are both located 3.5 inches fromsaid V₄ (VR₄) position share a common position in the different sets ofsensor positions.
 13. A universal ECG multiple sensor dermal precordialmask for fitting four different sizes of human bodies including extralarge for electrocardiographic recording of either the left or the rightside of a human chest using sensors V₁, V₂, V₃, V₄, V₅, and V₆ for theleft side recording disposed on one side of said mask, and VR₁, VR₂,VR₃, VR₄, V₅, and VR₆ for right side recording disposed on the oppositeside of said mask, said mask comprising a sheet of non-conductivematerial incorporating at least ten sensor positions for the placementof sensor electrodes forming four sets of sensor groups including fouralternate positions for each of the V₅ and V₆ (VR₅ and VR₆) positions,said ten sensor positions being disposed in a specific geometricarrangement with said V₁-V₄ (VR₁-VR₄) positions being utilized for allsizes of bodies, said V₅ and V₆ (VR₅ and VR₆) positions having first andsecond independent sensor positions each and first and second sharedpositions.
 14. The mask as set forth in claim 13 wherein said sensorsare printed on both sides of said mask with one side including said Vsensors and the reverse side including said VR sensors.
 15. The mask asset forth in claim 13 wherein said sensors are printed on the same sideof said mask with one half side thereof including said V sensors and theother half side thereof including said VR sensors.
 16. A mask as setforth in claims 14 or 15 wherein said sheet is flexible and disposable.17. A mask as set forth in claims 14 or 15 wherein said sheet isflexible and disposable.
 18. A mask as set forth in claim 13 whereinwhen said mask is utilized for a small size torso, said firstindependent V₅ (VR₅) sensor position closest to said V₄ (VR₄) positionis utilized along with said first shared V₅ and V₆ (VR₅ and VR₆)position which is also disposed closest to said V₄ (VR₄) position, whensaid mask is utilized for a medium size torso, said second independentV₅ (VR₅) sensor position, disposed furthest from said V₄ (VR₄) position,is utilized along with said second shared V₅ and V₆ (VR₅ and VR₆)position which is also disposed furthest from said V₄ (VR₄) position,when said mask is utilized for a large size torso, said first shared V₅and V₆ (VR₅ and VR₆) sensor position is utilized along with said firstindependent V₆ (VR₆) sensor position which is disposed closest to saidV₄ (VR₄) sensor position, and when said mask is utilized for an extralarge size torso, said second shared V₅ and V₆ (VR₅ and VR₆) sensorposition is utilized along with said second independent V₆ (VR₆) sensorposition which is disposed furthest from said V₄ (VR₄) sensor position.19. The mask as set forth in claim 18 wherein said V₁ and V₂ (VR₁ andVR₂) sensor positions are disposed equidistant from the patient'ssternum and on the fourth intercostal space, the center of said V₁ (VR₁)position is located approximately 2.0 inches from the center of said V₂(VR₂) position on the 270 (90) degree radial therefrom, the center ofsaid V₄ (VR₄) position is located approximately 3.5 inches from thecenter of said V₂ (VR₂) position on the 125 (235) degree radialtherefrom, the center of said V₃ (VR₃) position is disposed on a lineand equidistant between said V₂ (VR₂) and said V₄ (VR₄) positions, andsaid V₅ and V₆ (VR₅ and VR₆) positions have four alternative positionseach, all of said positions being disposed on a 90 (270) degree radialfrom said V₄ (VR₄) position, the centers of said V₅ (VR₅)positions beinglocated 1.75, 2.5, 3.5, and 5.0 inches therefrom and the centers of saidV₆ (VR₆) positions being located 3.5, 5.0, 7.0, and 10.0 inchestherefrom whereby the centers of said V₅ and V₆ (VR₅ and (VR₆) positionswhich are both located 3.5 and 5.0 inches from said V₄ (VR₄) positionshare a common position in the different sets of sensors.